package cn.fay.chapter15;

public class LinkedStack<T> {
	
	private static class Node<U>{
		
		U item;
		Node<U> next;
		
		Node(){
			item=null;next=null;
		}
		
		Node(U item,Node<U> next){
			this.item=item;
			this.next=next;
		}
		
		boolean end(){
			return item==null&&next==null;
		}
		
	}
	//末端哨兵
	private Node<T> top=new Node<T>();
	
	public void push(T item) {
		top=new Node<T>(item, top);
	}
	
	public T pop() {
		T result=top.item;
		if (!top.end()) {
			top=top.next;
		}
		return result;
	}
	
	public static void main(String[] args) {
		LinkedStack<String> ls=new LinkedStack<String>();
		for (String s : "The faith is to believe what you can not see".split(" ")) {
			ls.push(s);
		}
		String s;
		while ((s=ls.pop())!=null) {
			System.out.println(s);
		}
	}
}
